▎ 摘　　要

4d transition-metal- [(TM) = Ru and Rh] metal-graphite (MG) has a unique layered structure, where the TM monolayer is sandwiched between adjacent graphene sheets. The magnetic properties of TM-MG based on natural graphite are investigated using dc and ac magnetic susceptibility. (i) Ru-MG magnetically behaves like a quasi-two-dimensional ferromagnet. This compound undergoes successive magnetic phase transitions at T-cu (= 16.3+/-0.2 K) and T-cl (= 12.8+/-0.3 K). The origin of two phase transitions in Ru-MG is similar to that in stage-2 CoCl2 graphite intercalation compound (T-cu = 8.9 K and T-cl = 6.9-7.1 K), where the ferromagnetic layers are antiferromagnetically stacked along the c axis. The low-temperature phase below T-cl may be a reentrant spin-glass-like phase where the antiferromagnetic phase and spin-glass phase coexist. (ii) Rh-MG exhibits a superparamagnetic behavior. A ferromagnetic blocked state is formed below 9.7 K. The zero-field-cooled susceptibility shows a broad peak around 9.7 K. The irreversible effect of magnetization is observed below 13.5 K. The relaxation time obeys the Arrhenius law for thermal activation.